1. Field of the Invention
This invention relates to a process for producing a shaped product of collagen by syneresis.
2. Description of the Prior Art
There are known various kinds of shaped products consisting mainly of collagen. They are, for example, tubular products such as sausage casings, threadlike or stringy products such as sutures, spongy or feltlike products such as medical sponge, and tapes and sheets which are usable for a wide variety of applications.
A shaped product of collagen is formed from a pasty composition prepared by finely devided fibers of connective tissue containing collagen, such as the skin or tendons of an animal, and/or solubilized collagen or by the addition of one or more of fibrous materials, proteins, polysaccharides and synthetic high molecular materials to a collagenous substance. The product is obtained by a wet method such as the extrusion of the composition into a salt solution or by an electrochemical method such as electrodeposition.
A wet shaped product of collagen obtained by a wet or electrochemical method is usually very soft, as it contains a large amount of water. At least 95% of the product is water. The low pressure resistance of the product brings about a lot of difficulty in its drying, especially if it is a tubular product which is dried by the air introduced thereinto. Moreover, a large amount of energy and a correspondingly extensive set of equipment are required for removing a large amount of water from the product.